Commercial advertisers generally seek to generate increased use of their products or services through branding, which may include the repetition of an image or product name in an effort to associate related qualities with the brand in the minds of consumers. Different types of media may be used to deliver these messages, including traditional media such as newspapers, magazines, television, radio, outdoor or direct mail, or newer media such as websites and text messages. A challenge for advertisers is to induce the audience to be attentive to advertisements. To that end, many strategies have been employed over the years in several different mediums.
A Completely Automatic Public Turing Test to Tell Computers and Humans Apart (CAPTCHA) is a type of challenge-response test used in computing to ensure that the response is not generated by a computer. The process usually requires one computer (a server) asking a user to complete a simple test which the computer is able to generate and assess. Because other computers are generally unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human. Thus, it is sometimes described as a reverse Turing test, because it is administered by a machine and targeted to a human (in contrast to the standard Turing test that is typically administered by a human and targeted to a machine). A common type of CAPTCHA requires that the user type letters or digits from a distorted image that appears on a screen/display. Presently, CAPTCHAs involve engaging the user using random or pseudo-random word sets. As such, this time of user concentration is not being fully utilized by firms hosting web pages, and, by extension, their sponsors.